Dust extraction apparatus



May 7, 1935.

E. COFFIN El AL DUST EXTRACTION APPARATUS Filed Feb. 5, 1934 2 Sheets-Sheet 1 y 35- E. COFFIN HAL 2,000,662

DUST EXTRACTION APPARATUS Filed Feb. 5, 1934 2 Sheets-Sheet 2 Patented May 7, 1935 7 2,000,662 DUs'r-ExTRAc'rIoN APPARATUS I Ernest Coffin and Flix Frederic Ruau,

Deptford, London, England Application February 5, 1934, Serial No. 709,882

In Great Britain 6 Claims.

- This invention is for improvements in or relating to dust extraction apparatus for use on machines handling dusty material, for example, tobacco feeding apparatus such as-is used on cigarette making machines or the like.

The object of the invention is to provide im proved means whereby dust from the material may be removed from the machine more efficiently than has hitherto been possible and without removing any of the useful portions of the material in question. In the case of a tobacco feeding apparatus for a cigarette machine, the invention is preferably applied to operate on the tobacco at the point where the tobacco is finally discharged. (usually by means of a picker roller operating ona carded distributor) from the feeding apparatus, and in this case it is of great importance that there should not be any. surfaces on which the dust may accumulate and from which it mightdrop periodically and spoil the resulting cigarettes.

It has previously been customary to shroud the tobacco picking roller in order to collect the dust, but it is found in practice that the dust is inclined to adhere very firmly to such shrouds, particularly when the dust is damp.

The invention eliminates all shrouds and such surfaces which are in closeproximity to the rotating picker roller are designed, for instance, by making them rotatable to avoid any accumulation.

It is also found that bydispensing with the customary shroud, the dust collected is kept much more free of actual particles of long or short tobacco which it is not desired to extract with the dust than in the machines hitherto used.

The present invention consists of a dust ex-' traction device for machines handling dusty material comprising dust arresting'surfaces situated at the points where the dust is principally raised (e. g. near the picker rollers of tobacco feeding apparatus) means for scraping or otherwise cleaning said surfaces andsuction means for carrying the dust away. Preferably the dust arresting surfaces are movable in which case they are conveniently formed as rollers.

The invention-will be more particularly described with reference to the accompanying drawings in which:- A

Figure 1 is a diagram of a tobacco feeding apparatus showing the invention applied thereto.

Figure 2 is a sectional elevation of a part of Figure 1 showing the invention in more detail.

Figure 3 is a side view of another portion of the rA EnroFFicE February 11, 1933 apparatus constructed in accordance with the invention.

Figure i is an endelevation of Figure 3. l

Figure'5 is a view of a detail Figure 6 is a bottom view of Figure 5. r

Like freferences refer to like parts throughout the specification and drawings. v

' Referring to Figural tobacco is fed from 'a hopper l to a'combing roller 2 above which is located a brushing roller 3 to evenly distribute the tobacco over the surface of thecombing roller 2. Located in front of and beneath the combing roller 2 is a distributor inthe form ofa carded roller 4 and the tobacco on the combing roller u is picked. from the surface thereof by a rotating roller 5 and showered on to the distributord.

The distributor 4 carries the tobacco beneath a series of magnets 6 which remove any fragments of iron or steel and the tobacco is thenpicked from the distributor 4 by another picker' roller 1 and showered into the trough 8 of the rod forming mechanism of a cigarette making machine. A

Situated in close proximity to the picker roller 1 is a suction conduit 9 the mouth or suction duct 9a of which extends parallel to the axis of the picker roller, the conduit being adapted to suck the dust away from the-tobacco as explained hereinafter, allowing only the shreds of'tobacco to fallinto the trough of the cigarette making machine.

In accordance'with the present invention dust arresting surfaces are provided which are shown in the'drawings as rollers Hi and II which are rotatable and arranged so that their surfaces are close to the path swept outby the pins of the picker roller.

The rollers l0 and are geared together by gears l2 and I3,' see Figure '4 and are rotated by a ratchet and pawl mechanism, a ratchet I4 being secured to the spindleof the roller I I and operated by a pawl l5 .carried 'on a pivoted arm l6 which. is periodically operated by pins 11 carriedon' a. sprocket Wheel l8 driven from the main drive of the machine. duct 9a which is. in proximity with the rollers l0 and II is arranged toengage with the rollers and is provided with sharp edges l9 and 20 which bear on the rollers andact as scrapers.

The rollers I 8 and II rotate in such a direction that the surfaces move towards the scrapers I9 and 20 formed by the edges of the .duct so that as the dust is deposited it is scraped off and lies in the mouth of the duct and is consequently carried through the suction apparatus with dust The end of the difierent points of the duct immediately with the j fan inlet at the remote end of the conduit and in this way the suction head is practically constant whereas with an open conduit there is a continual drop in head roughly proportional to the distance from the fan. 7

In order to increase the efiiciency ofthe apparatus the inlet from the duct .to the conduit may be of restricted or nozzle formation as shown in Figure 5 to increase the velocity of the air.

It is found in a tobacco feeding apparatus of the type above described that dust tends to accumulate on the forward wall 22a of the trough of the cigarette making machine from which it is liable ,to fall into the filling trough .of the machine. In order to prevent the accumulation of dust at this point the forward wall 22a is wall 22a .and'sogvibrate the wall when any dust which adhering thereto is shaken oif and is sucked up by the duct 9a 'together'with the dust taken from the rollers M! and; H and the suspended dust,

n is to be understood that the above description and application of the invention to a'tobacco feeding mechanism'is only given byway of example ,as instead of having rollers it would be possible to effect the desired object by using fixed dust arresting surfaces having gmovable scrapers ctr-operated therewith and further although theinvention has been described as applying to the final picker of the machine, it is equally applicable to other pickers or any points where the operation of the machine produces .a quantity of dust. 7

What we claim .as our invention and desire to jacent said picker roller and spaced apart from each other to provide a freepassage between said elements, and a suction duct extending lengthwise or said elements connected at .one end with a source of suctionand at the other end engaging the dust arresting elements and forming a continuation of the passage formed between said elements.

2. Inapparatus for feeding tobacco, the com- 7 bination with a carded conveyor for the tobacco, of a picker roller having projections thereon for removing the tobacco from said conveyor, a pair of movable dust arresting elements located adja cent said picker roller and spaced apart from each other to provide a free passage between said elements, and a suction duct extending lengthwise of said elements connected at one end with a source of suction and at the other end engaging the dust arresting elements and forming a con- ,tinuation of the passage formed between said elements, said suction duct having partitions which divide it lengthwise and which equalize the sucarresting elements and forming a continuation:

of the passage formed between said elements.

4. In apparatus for feeding tobacco, the combination with a carded conveyor for the tobacco, of a piclrer rollerhaving projections thereon for removing the tobacco from said conveyor, a pair of movable dust arresting elements located adjacent said picker roller and spaced apart from each other to provide a free passage between said elements, and a suction duct of nozzle formation connected at its larger end with a source of suction, and at its restricted end engaging the dust arresting elements and fo'rming ,a continuation of the passage formed between said elements, said suction duct having partitions which divide it lengthwise and which-equalize the suction along the duct.

5. In apparatus for feeding tobacco, the combination with a carded conveyor forthe tobacco, of

a picker roller having projections thereon for removing the tobacco from said conveyor, 2. pair of rotatable rollers located adjacent said picker roller and spaced apart from and geared to each other, a ratchet wheel fixed to one .of said rollers, a pawlto engage with and operate said ratchet,

and a suction duct'connected at one end with a source of suction and at the other end engaging said rollers and forming a continuation of the space formed between the rollers.

6. In apparatus for feeding tobacco, the combinationwith a carded conveyor for the tobacco, of

a picker roller having projections thereon for removing the tobacco from said conveyor, a pair of rotatable rollers locatedadjacent said picker roller and spaced apart from and geared to each other, a ratchet wheel fixed to .one of said rollers, a pawl to engage with and operate said ratchet, and a suction duct connected at one end with a source of suction and at the other end engaging said rollers and forming a continuation of the space formed between the rollers, said suction duct having partitions which divide it lengthwise and which equalize the suction along the duct.

FELIX FREDERIC RUAU, ERNEST CQEFIN. 

